UPDATE:
I was on Ridley Creek yesterday afternoon, and saw Dave again. He was fishing upstream about 200 yards, and we said Hey. The trout weren't
taking any of the usual stuff, and I saw a flash about six feet in front of me.
I decided to tie on a #16 red chironomid pattern that I had two of, and hooked one on the first cast!

Dave had made his way downstream of me by now, and was throwing
something at a large trout that was holding on the opposite bank. After a
few more casts, I suggested he try one of the chironomids I had. BANG! The
biggest trout I've ever seen in person took the fly, shot clean out of the
water, and spit the hook! Dave should have kept using that fly, but switched
to a pink San Juan Worm, and was still casting to that trout when I drove
away. I should've had a video camera rolling... that trout was HUGE !